A sliding door assembly for a stackable sliding wall is known from EP 0 953 706 B2. With sliding door assemblies or with lift and slide door assemblies which are used as part of the glazing of a building, there is the problem that in particular door leaves having multiple glazing can be very heavy, and may weigh for example 200 kilograms or more. If such a door leaf is to be displaceable not manually, but driven by a motor, the drive motor has to provide a correspondingly high motive force. At the same time, however, for visual reasons the drive motor should only take up as little installation space as possible.